Drug Modulators of B Cell Signaling Pathways and Epstein-Barr Virus Lytic Activation

Area of Science:

• Virology
• Immunology
• Pharmacology

Background:

• Epstein-Barr virus (EBV) establishes lifelong latency in B cells.
• B cell receptor (BCR) signaling is crucial for B cell function and can reactivate EBV.
• Understanding EBV reactivation pathways is key for managing EBV-associated diseases.

Purpose of the Study:

• To investigate the role of BCR signaling in EBV lytic induction.
• To evaluate the efficacy of BCR inhibitors and immunosuppressive drugs on EBV reactivation.
• To determine if BCR-mediated EBV activation occurs in primary patient B cells.

Main Methods:

• Utilized cell lines and primary peripheral blood mononuclear cells (PBBMCS).
• Administered drugs targeting BCR signaling (ibrutinib, idelalisib, dasatinib) and immunosuppressants (cyclosporine, tacrolimus, rapamycin).
• Assessed EBV lytic induction and BCR signaling pathways.

Main Results:

• BCR inhibitors (ibrutinib, idelalisib, dasatinib) effectively blocked BCR-mediated EBV lytic induction.
• Cyclosporine and tacrolimus inhibited BCR-mediated EBV reactivation, but rapamycin did not.
• mTORC2 signaling was found to contribute to BCR-mediated EBV lytic induction.
• BCR signaling activated EBV lytic induction in primary patient B cells, inhibited by ibrutinib and idelalisib.

Conclusions:

• BCR signaling is a critical pathway for EBV lytic induction.
• Clinically relevant BCR inhibitors can block EBV reactivation.
• Targeting BCR signaling offers a potential therapeutic strategy for EBV-associated conditions.